gdb/riscv: correct dwarf to gdb register number mapping

According to the riscv psabi, the mapping relationship between the
DWARF registers and the machine registers is as follows:

  DWARF Number | Register Name | Description
  0 - 31       | x0 - x31      | Integer Registers
  32 - 63      | f0 - f31      | Floating-point Registers

This is not modelled quite right in riscv_dwarf_reg_to_regnum, the
DWARF register numbers 31 and 63 are not handled correctly due to a
use of '<' instead of '<='.  This commit fixes this issue.

diff --git a/gdb/riscv-tdep.c b/gdb/riscv-tdep.c
index 0a050b272ffff6d579dae2ee7701671f85211ee4..a298623b44921947135f0ff6882d0d01de3d4039 100644 (file)
--- a/gdb/riscv-tdep.c
+++ b/gdb/riscv-tdep.c
@@ -3623,10 +3623,10 @@ riscv_add_reggroups (struct gdbarch *gdbarch)
 static int
 riscv_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int reg)
 {
-  if (reg < RISCV_DWARF_REGNUM_X31)
+  if (reg <= RISCV_DWARF_REGNUM_X31)
     return RISCV_ZERO_REGNUM + (reg - RISCV_DWARF_REGNUM_X0);
 
-  else if (reg < RISCV_DWARF_REGNUM_F31)
+  else if (reg <= RISCV_DWARF_REGNUM_F31)
     return RISCV_FIRST_FP_REGNUM + (reg - RISCV_DWARF_REGNUM_F0);
 
   else if (reg >= RISCV_DWARF_FIRST_CSR && reg <= RISCV_DWARF_LAST_CSR)